Imprinter apparatus for packaging machines



Oct. 25, 1966 w. E. YOUNG ETAL 3,280,728

IMPRINTER APPARATUS FOR PACKAGING MACHINES Filed April 19, 1965 6 Sheets-Sheet l INVENTIJOR.

ROBERT O. WOLFELSPERGER HARRY JOHNSON ATTORNEY Oct. 25, 1966 w. E. YOUNG ETAL 3,230,728

IMPRINTER APPARATUS FUR PACKAGING MACHINES Filed April 19, 1965 6 Sheets-Sheet 2 INVENTORS WILLIAM E. YOUNG ROBERT O.WOLFEL$PERGER HARRY JOHNSON BY (9M1 flaw ATTORNEY Oct. 25, 1966 w. E. .YOUNG ETAL 3,280,723

IMPRINTER APPARATUS FOR PACKAGING MACHINES 6 Sheets-Sheet 5 Filed April 19, 1965 INVENTORS WILLIAM E. YOUNG R E G R E P s L E F L o W O T R E B 0 R Y E N R O T T A Oct. 25, 1966 w. E. YOUNG ETAL 3,280,728

IMPRINTER APPARATUS FOR PACKAGING MACHINES Filed April 19, 1965 6 Sheets-Sheet 4 INVENTORS WILLIAM E. YOUNG R E 6 m PM w S N H F 0 MJ W Y T m E w 0V R Y B Y E N R O T T A Oct. 25, 1966 w. E. YOUNG ETAL 3,280,728

IMPRINTER APPARATUS FOR PACKAGING MACHINES 6 Sheets-Sheet 5 Filed April 19, 1965 INVENTORS WILLIAM E. YOUNG ROBERT O. WOLFELSPERGER HARRY JOHNSON BY ATTORNEY Oct. 25, 1966 w. E. YOUNG ETAL 3,280,728

IMPRINTER APPARATUS FOR PACKAGING MACHINES Filed April 19, 1965 6 Sheets-Sheet 6 WILLIAM E. YOUNG ROBERT O. WOLFELSPERGER HARRY JOHNSON BYMJ QM ATTORNEY United States Patent Ofiice 3,280,728 Patented Oct. 25, 1966 3,280,728 IMPRINTER APPARATUS FOR PACKAGING MACHINES William E. Young, Stamford, Conn, and Robert 0. W01- felsperger, Fairlield, and Harry Johnson, West Paterson, N.J., assiguors to Milprint, Inc., Milwaukee, Wis., a corporation of Delaware Filed Apr. 19, 1965, Ser. No. 449,162 5 Claims. (Cl. 101-25) The general technological field to which this invention pertains is packaging machines that enclose a commodity in flexible packaging film, which can be by any of several means such as wrapping the film around the commodity or converting the rolls of film into containers for receiving the commodity. More particularly, this invention relates to an imprinting machine for use with packaging machines and which is adapted to imprint a legend on the Web of packaging film used by the machine; in a still more specific sense, the imprinter of this invention is designed to imprint a legend on a pre-printed Web of film in packaging machines, which legend will be properly registered with the pre-printed design on the web.

The film used in packaging machines is often a printed web which includes general information concerning the product or its manufacturer, as well as specific information about the product such as its name, ingredients, weight, price, etc. If the machine is used to package a variety of products, each individual product will require its own printed web, which can force the packager to carry a large inventory of differently printed films. Some packagers seek to alleviate the situation by using webs with standardized pre-printed designs and then applying labels to the finished packages to identify the individual products; while this can eliminate some inventory problems, labelling involves substantial costs of inserting or attaching labels, as well as inventory and storage problems.

A main object of this invention is to provide an imprinting machine that can be attached to a packaging machine and which is adapted to imprint a selected legend on a moving web of film used by the packaging machine before the web is used to enclose a commodity to be packaged. This feature is especially useful in that it will permit a packager to use a web with a pre-printed standardized design that is applicable to a large number of commodities and then use the imprinter machine of this invent-ion to apply a selected legend to the pre-printed web to identify particular commodities. As an example of such use, a meat packer may desire to package several dozens of different kinds of luncheon meats and cheeses, which could force him to carry a separate roll of printed film for each different item; however, with the imprinter of this invention, he can adopt a pre-printed web of standard design that will apply to all products and then use the imprinter to add appropriate legends for individual product identity to the pre-printed material. A related object of this invention is to provide an imprinter of the foregoing type which will include means for obtaining proper registry of the imprinted legend with the preprinted design on the web in the event that the imprinted legend should become out of registry.

Another main object of this invention is to provide an imprinter of the foregoing type with a printing plate cylinder which can be easily removed from the machine in order to allow facile change of the printing plate mounted on the cylinder. This feature will permit the user to rapidly change the individual legends applied by the imprinter so that the imprinter uni-t can quickly accommodate to changes in the commodity being packaged and/or to changes in the imprinted legend. A collateral object is to provide magnetic means for attaching printing plates to the cylinder in the imprinter so that the user can change the plates on the cylinder in a minimum amount of time.

Another main object of this invention is to provide an imprinter of the type described which uses a solvent-free ink. This eliminates the need for including drying apparatus for solvent removal and thereby facilitates installation of the imprinter on a packaging machine where space is almost always at a premium. This also enables the imprinter of this invention to be used to print on relatively impervious or non-absorbent films of the type which are widely used in packaging machines that the present imprinter is intended to be used with. Also, this allows the imprinter to be used on machines for packaging foods without engendering sanitation problems as could be caused by a solvent-type ink from which the solvent would have to be removed in order to dry the ink. Still in relation to the ink system used in the imprinter of this invention, another object is to provide a mechanism wherein the printing plate cylinder may revolve constantly but the ink is on a carrier which moves intermittently and only when the web of packaging film is in the selected printing position in order to thereby conserve the amount of ink used by the imprinter.

Another important object of this invention is to provide an imprinter of the subject type which can be driven from the packaging machine itself so as to eliminate the need for a second power train and reduce the problems of obtaining proper registration between the imprinted legend applied by the imprinter and any pre-printed design on the web of the packaging itself.

The foregoing and other more specific objects will appear in the description which follows. In the description, reference is made to the accompanying drawings which form a part hereof and in which a specific form of this invention is shown. This form will be described in detail to enable those skilled in the art to practice this invention, but it is to be understood that other embodiments of the invention may be used and that structural changes in the embodiment described herein may be made by those skilled in the art without departing from the true scope of the present invention. The ensuing is intended to be illustrative, however, and not to limit the present invention. Like reference characters refer to like parts in the several drawings and although various details of structure are identified by specific names for clarity of description, such names should be construed in a generic sense.

In the drawings:

FIG. 1 is a perspective view showing an imprinter of the present invention installed on a packaging machine;

FIG. 2 is a perspective view of a portion of the imprinter from FIG. 1 illustrating the action of the imprinter of the present invention;

FIG. 3 is a perspective view showing a typical package made by the machine of FIG. 1;

FIG. 4 is a side view with portions broken away illustrating the imprinter of this invention;

FIG. 5 is a horizontal, sectional view, with portions broken away, taken along the plane of line 55 of FIG. 4;

FIG. 6 is a horizontal sectional view of part of FIG. 5 taken along the plane of lines 66 in FIG. 5;

FIG. 7 is a partial side view with portions broken away showing a gear train associated with the printing cylinder of the imprinter;

FIG. 8 is a vertical sectional view, with portions broken away, taken along the plane of line 88 in FIG. 7;

FIG. 9 is a vertical sectional view, with portions broken away, taken along the plane of line 99 in FIG. 4;

FIG. 10 is a vertical sectional view of part of the printing cylinder of the imprinter taken along the plane of line 1010 of FIG. 9;

FIG. 11 is an enlarged side view of part of the mechanism of FIG. 4; and

FIG. 12 is a perspective view of the printing cylinder assembly of the imprinter.

FIG. 1 illustrates a general view of an imprinter 1 of the present invention installed on a widely used type of packaging machine 2. Before proceeding to a detailed description of the present invention, the general nature and operation of the packaging machine 2 will be first described in order to more clearly point out the functioning of the imprinter of this invention and its relation to a packaging machine.

PACKAGING MACHINE AND ITS OPERATION A packaging machine 2 as shown in FIG. 1 is adapted to utilize two webs of film to enclose a commodity by forming containers from one web of film and heat sealing the other web of film to the containers after a commodity has been inserted therein; the packages may be evacuated or gas-filled if so desired. The machine 2 includes spaced side frames 3 which carry its various associated mechanisms. At one end of the machine, a first web 4 of thermoplastic material is carried on a supply roll 5 mounted on the machine and is fed in the direction shown by the arrows 6 onto a rotatable vacuum-forming drum 7 which vacuum forms the web 4 into double rows of containers surrounded by flange portions. The drum 7 rotates in the direction of the arrow 8 to carry the film underneath a bank of heating tubes indicated generally as 9 to form the web into such containers.

At the other end of the machine, stacks 10 of commodity to be packaged are carried along a conveyor 11 and onto a second web 12 which may also be thermoplastic packaging material, fed from a roll thereof carried on a supply shaft 13. After leaving the exit end of the conveyor 11, the second web 12 carrying the stacks 10 of commodity travels to the lower portion of the vacuumforming drum 7, over suitable supporting structure, and the vacuum-formed containers of the first web 4 are fitted over the stacks 10 of the product. The superimposed webs 4 and 12 are then fed to a heat-sealing station, not shown, underneath the drum where the two webs are jointed to one another; if the completed package is to be evacuated and gas-filled, small passages are left in the heat seals between the two webs and the packages continue to an evacuation and final heat sealing head, not shown, for these latter operations. Suitable cutting means, not shown, separate the joined webs into individual packages and the sealed and completed packages 14 depart from the machine along an output chute 15 from which they may be carried by suitable conveyor, not shown.

A typical package 14 formed by the packaging machine 2 is shown in FIG. 3. The upper part of the package consists of a container 4a vacuum-formed from a portion of the web 4 and the bottom part of the package consists of a portion 12a from the second web 12 of the machine, the portion 12a being heat sealed to the portion 4a of the container along the peripheral flanges 16 of the portion 4a which surrounds the commodity cavity formed therein and in which the stack 10 of the product is received.

The packaging machine 2 has been described briefly in order to more clearly set forth the action of the imprinter of the present invention. However, it is stressed that the imprinter of this invention may be used on a wide variety of packaging machines and is not limited to use with the machine 2 of the type illustrated herein. Also, the imprinter 1 is shown in the drawings as acting upon the first web 4 used in the machine, which web is often referred to as the formed Web by those in the packaging art since it is the web which is thermo-formed into a container by the machine 2; however, the imprinter 1 of this invention may also be installed on the second web 12, which is often referred to as the flat web, since its shape is not altered by the machine when forming the packages. The packaging machine 2 forms no part of the present invention and a machine of the type illustrated is set forth in detail in United States Letters Patent No. 2,935,828.

IMPRINTER DESCRIPTION The general action of the imprinter of this invention is shown schematically in FIG. 2. The imprinter 1 includes a rotating printing plate cylinder assembly 20 to which a pair of printing plates 21 are attached, there being only one such plate visible in FIG. 2. The web 4 of packaging film supplied to the packaging machine 2 has two rows of a pre-printed design 22, each design being intended for a separate package. As the web 4 passes over the printing plate cylinder 20 of the imprinter, an auxiliary legend 23 is printed on the web 4 in a selected position vis-a-vis the design 22, the legend 23 being imprinted by the plates 21 carried on the cylinder. In a typical use of the imprinter, the design 22 will be a background design common to several types of commodities and the imprinted legend 23 will consist of variable information for specific products, such as product name, ingredients, etc. through the use of the imprinter, a packager can adopt a pre-printed Web 4 which can be used with many diverse commodities and then merely alter the im printed legend 23 for each individual commodity. The present invention relates to the combination and organization of elements and mechanisms which can accomplish this results in an efficacious manner.

(a) Drive system for the imprinter The mechanical elements of the imprinter 1 are supported in a frame shown herein as comprising, referring now to FIG. 1, a main beam 25, a pair of spaced side walls 26 and 27, a bottom 28 and a rear wall 29. As best shown in FIG. 4, the main beam. 25 is securely attached to a shaft 30, which is part of the packaging machine 2, by means of a clamp ring 31. The side wall 26 and the bottom 28 are attched to the main beam 25, and the side wall 27 is attached to the outer end of the bottom. The rear wall 29 is attached to the main beam on the opposite side from the side wall 26. For the most part, the elements associated with the mechanical drive for the imprinter are carried in the space between the side wall 26 and the rear wall 29, whereas the functioning elements of the imprinter which act upon a web of packaging film are carried between the side walls 26 and 27, with some of the shafts journaled in the side walls and other shafts, such as the shaft 5, cantilevered from the main beam 25. A cover 32 may be joined to the side wall 26 and the rear wall 29 to protect the mechanisms situated between the two Walls.

The imprinter 1 is driven by a motor, not shown, associated with the packaging machine 2 for driving the vacuum-forming drum 7. As shown in FIG. 4, a shaft 35 on the packaging machine 2 is driven by the motor and carries a sprocket 36- which is connected through a chain 37 to a sprocket 38 carried on a main drive shaft 39 which is journaled in the side wall 26 and the rear wall 29. The shaft 39 carries three other sprockets, not shown in the drawings, which are connected through chains 40, 41 and 42 to other elements of the imprinter which will be described hereafter. Idler sprockets 43 are mounted on adjustable brackets for setting the proper tension in the various chains.

(b) Back-up roller assembly With reference now to FIG. 9, two of the principal elements of the imprinter 1 are a printing plate cylinder assembly 20 which carries the printing plates for the legend to be applied by the imprinter and a back-up roller assembly 45 which is spaced on the opposite side of the web of material to be printed from the printing plate cylinder assembly and provides for sufiicient pressure for imprinting the web, and also to carry the transmission system for driving the printing plate cylinder. In order to satisfy certain objects of this invention, the back-up roller assembly is fixed in position on the frame of the imprinter but the printing plate assembly is arranged to be easily removed as an integral unit. A pivotable rocker arm 46 shown in detail in FIG. 11 is attached by a pivot pin 47 to each side wall 26 and 27, see also FIG. 4. Turning now to FIG. 9, rocker arm 46a is pivoted to the inside of side wall 27 and the rocker arm 46]) is pivoted to the exterior of the side wall 26. y The back-up roller assembly 45 includes a central shaft 48 which is journaled in suitable bearings 49 and 50 carried in the rocker arms 46a and 46b respectively. The central shaft 48 extends through a slot 51 in the side Wall 26 and the end of the shaft projects beyond the wall in order to carry the drive mechanism described below.

Near the outer end of the central shaft 48 of the backup roller assembly, a sprocket 52 is attached to a cage 53 carried on a sleeve bearing fitted on shaft 48. An internal gear 54 attached to the cage 53 meshes with a planetary gear 55 carried on a shaft 56 that is joined to a block 57 which is keyed to the shaft 48. The sprocket 52 is meshed with chain 41 (FIG. 4) connected to a sprocket, not shown, attached to the main drive shaft 39 so that power from the motor of the packaging machine will be transmitted through chains 37 and 41 respectively to drive the shaft 48 through sprocket 52, cage 53, internal gear 54, planetary gear 55 and block 57 respectively. This train constitutes the main drive of the back-up roller assembly 45 and it will be constantly turning during normal operation of the packaging machine.

For reasons hereinafter stated, provision is also made for manual movement of the back-up roller assembly. This comprises a shaft 60 which is carried in the rocker arms 46a and 46b and passes through slots 61 and 62 formed in the side walls 26 and 27 respectively. At one of its ends, the shaft 60 carries a bevel gear 63 which meshes with a bevel gear 64 carried on a vertical shaft 65 supported in brackets 66 and 67 attached to the rocker arm 46b. The central portion of the vertical shaft 65 carries a worm 68 which meshes with a worm gear 69 attached to a hollow pinion 70 journaled on the shaft 48 on a suitable sleeve bearing. The pinion 70 meshes with the planetary :gear 55 so that manual rotation of the shaft 60 will be transmitted through the gear trains described above to alter the speed of rotation of the gear 55 and, hence, the rotation or position of the shaft 48.

Means are provided on the imprinter for reciprocating the rocker arms 46a and 46b between a first position in which the back-up roller assembly 45 exerts pressure against the raised portions of printing plates carried on the printing plate cylinder assembly 20 in order to cause a legend to be imprinted on the web of packaging film and a second position in which the back-up roller assembly 45 is raised upwardly from the first position. For this purpose, referring now to FIG. 4, each rocker arm is actuated by an air cylinder 74 that, turning now to FIG. 11, has a reciprocable shaft 75 which is joined to an intermediate portion of each rocker arm 46. The rocker arm in FIG. 11 is shown in its first position and a latch means indicated generally as 76, including a stop 77 attached to a side wall of the imprinter and a block 78 attached to each rocker arm, is provided to hold each rocker arm in its uppermost or its second position. Returning to FIG. 4, the upper end of each shaft 75 of the air cylinders extends through a bar 79 (see also FIG. 1) attached to the frame of the imprinter and an adjustable nut 80 is attached to its outer end to provide a mechanical stop for controlling the first position, or downwardmost position, of each rocker arm. This position is adjusted so that the back-up roller will exert the desired pressure against the printing cylinder only when the raised portions of printing plates carried on the printing cylinder are in the position for imprinting a legend on a web of packaging film passing through the imprinter. The central shaft 48 carries a rubber covered roller 81 which contacts the web of packaging film passing over the printing plates.

(0) Printing plate cylinder assembly Referring now to FIG. 9, the printing plate cylinder assembly 20 includes a hollow central shaft 85 and is driven from a gear 86 keyed to the central shaft 48 of the back-up roller assembly 45 and, referring now to FIGS. 6 and 7, the gear 86 meshes with a gear 87 journaled on bearings 88 carried on a stub shaft 89, threaded into the side wall 26. The gear 87 meshes with a gear 90 which is journaled on bearings 91 carried on a stub shaft 92 that is threaded into a plate 93 secured to the side wall 26. The gear 90 meshes with a gear 94 (see also FIG. 9) keyed onto the central hollow shaft 85 of the printing plate cylinder assembly 20. In this fashion rotation of the shaft 48 drives the printing plate cylinder assembly 20 through the train of gears 86, 87, 90 and 94.

Turning now to FIG. 9 one end of the aforementioned central hollow shaft 85 of the printing plate cylinder assembly 20 is journaled in a bearing 95 mounted in an end wall 96 attached to a base plate 97, and the opposite end of the shaft 85 is journaled in a bearing 98 mounted in a second end wall 99 attached to the base plate 97. The base plate 97 and end walls 96 and 99 provide a drawerlike support means for holding all of the units of the printing plate cylinder assembly 20 and so that the assembly is adapted to be moved into and out of the frame of the imprinter as an integral unit. This feature facilitates quick change of the printing plates when it is desired to change the imprinted legend. This unit arrangement of the printing plate cylinder assembly 20 is best shown in FIG. 12. Suitable apertures are formed in the side walls 26 and 27 to receive the assembly. The shaft 85 extends through the wall 99 and a knob 100 is attached to its outer end to allow for manual turning of the shaft.

For the purposes explained below, a tubular electric heater 103 extends through the side wall 26 of the imprinter and is positioned inside the hollow shaft 85 in the manner shown in the drawings; the heater 103 is held in place against the wall 26 by means of a clamp 104 and its outer end is inserted in a socket 105 for connect-ion to an electrical power source, not shown.

Two printing plate cylinders 106 are carried on the shaft 85, each cylinder 106 being of identical construction. A cylinder 106 includes a pair of opposed longitudinal grooves 107 (see FIG. 10) and a guide pin 108 fixed in position near each end of each groove 107. The pins 108 extend slightly above the outer surface of each cylinder 106. A magnet 109 is inserted in each groove 107, there being a hole near both ends of the magnet 109 through which the pins 108 extend, and each magnet is U-shaped with its legs terminating at the outer surface of a cylinder 106. A curved printing plate 21, which carries the selected legend to be applied by the imprinter, is fitted over each groove 107 and held in place by a magnet 109 with the guide pins 108 extending through spaced holes in each plate to aid in maintaining the proper positioning of the plates on the cylinder. Although each cylinder is shown herein as having two such printing plates, one plate or more than two plates could also be carried on a cylinder. As shown in FIG. 10, a set screw 110 is inserted through each cylinder 106 and engages a key which fits into a mating slot formed in the hollow shaft 85 so as to secure a cylinder 106 to the shaft 85; several set screws 110 may be used with each cylinder 106 if desired.

A grooved temperature sensing element 112 is fixed near one end of the shaft 85 and a cooperating member 113 is mounted in a bracket 114 attached to the base plate 97. The elements 112 and 113 measure the temperature of the shaft 85 and control the operation of the heater 103 to ensure that the shaft temperature does not exceed suitable limits and they are connected through wires not shown to well-known temperature apparatus, also not shown for this purpose.

((1) Roll leaf supply system Instead of a solvent-type ink which would require drying apparatus and interfere with its intended operation, the imprinter of this invention uses roll leaf which comprises pigment disposed on a carrier web of suitable film and wherein the pigment can be transferred to the film to be printed by the application of heat and pressure. The carrier web can be of any suitable material, cellophane, acetate and polyester films being in common use. Several coatings, either combined or separate, are applied to the carrier web, including a color coating of the desired type, a release coating which melts when heated to separate all the coating from the carrier, and a size coating which acts as the bonding agent betweenthe roll leaf and the film being imprinted. When heat and pressure for a suitable dwell time are applied, the film tobe imprinted softens slightly and is impregnated with the size coating of the roll leaf and the coatings separate from the carrier web and become joined to the imprinted film. Materials of this type are well-known and are commercially available from several suppliers. The term roll leaf as used herein refers to such material.

Turning to FIG. 4 a supply roll of a web 117 of roll leaf is wound on a supply reel 118 caried on a fixed shaft 119 supported in the beam 25 of the frame of the imprinter near the roll of web 4. The web 117 of roll leaf is led from the reel 118 and around idler shafts 120 and 121, over the printing plate cylinders 106, over idler shaft 122 and thence onto a rotatable rewind shaft 124. The idler shafts 120, 121 and 122 and the rewind shaft 124 are all suitably journaled in the frame of the imprinter.

The rewind shaft 124 is driven by means of a sprocket 125 keyed to the shaft, and the sprocket 125 meshes with chain 42 connected to a sprocket, not visible in the drawing, keyed to the main drive shaft 39 (see also FIG. Thus, the rewind shaft 124 is continuously driven during operation of the packaging machine 2. However, the web 117 is not continuously drawn onto the shaft 124 because of the action of the hereafter described clutch means between the shaft 124 and the web.

Turning now to FIGS. 5 and 6, a Web 117 is joined to a sleeve 126 which is fitted over the rewind shaft 124. The connection between the shaft 124 and the sleeve 126, best shown in FIG. 6, is a slipping clutch arrangement wherein the shaft 124 has a groove 127 underneath the sleeve 126, a movable member 128 is inserted in the groove by means of bolts 129 threaded into the shaft 124, and springs 130 are inserted between the bottom of the groove 127 and the movable member 128 so as to urge the movable member outwardly to engage the inner surface of the sleeve 126. The supply reel 118 is carried in a sleeve 131 on the supply shaft 119. As mentioned previously in connection with the description of the printing plate cylinder assembly 20, the shaft 85 carries two printing plate cylinders placed side-by-side. Each cylinder has its own roll leaf system which means that the shaft 119 will have two supply reels 118 and the shaft 124 will have two sleeves 126.

Turning now to FIG. 4, a brake means indicated generally by the numeral 135 is attached to the frame of the imprinter in such manner as to exert a braking force on each web 117 of roll leaf carried on a supply reel 118. The brake means 135 includes an arm 136 pivoted about a shaft 137 mounted to the beam 25 of the frame. At the outer end of the arm 136, a weight 138 is attached and is adapted to bear against a Web 117 carried in a supply reel 118, which position is shown in full-line in FIG. 4. When a supply roll of web 117 is inserted on shaft 119, the arm 136 is raised to the dotted-line position shown in FIG. 4 and then placed on the web when the reel is in proper position.

A microswitch 139, which is connected to a suitable power source not shown, can be attached to the frame and adapted to actuate an indicator light when the arm 136 reaches a low position upon consumption of web 117 to give a visual warning when the supply of roll leaf is low enough for the operator to consider replenishing the roll leaf. The warning light can be mounted on control panel 140 supported on pedestal 141 attached to the frame of the imprinter.

The action of the above described means for supplying roll leaf to the imprinter of this invention is as follows. Before starting the packaging machine, a web 117 of roll leaf is threaded from the supply reel 118 over the several idler shafts and between the back-up roller and the printing plate cylinders of the imprinter onto sleeve 126 on the rewind shaft 124. The brake arm 136 is lowered to rest upon the supply reel of roll leaf. When the packaging machine operates, the rewind shaft 124 is constantly driven but the tension or force exerted on the web 117 of roll leaf by the brake arm 136 is substantially greater than the tension exerted on the web 117 by the slipping clutches in the shaft 124. In a typical installation, the weight 138 on the brake arm 136 is selected to exert a tension of approximately thirty ounces on the web of roll leaf and the slipping clutches in the rewind shaft are selected to exert a tension of approximately one ounce on the Web. With this arrangement, the brake means acts to prevent movement of the web 117 onto the sleeve 126 and the slipping clutches act to take up any slack in the web of roll leaf so that it is relatively taut. The imprinter places an imprinted legend on the Web of packaging film when the raised portions of the printing plates 21 carried on the printing plate assembly pass beneath the back-up roller of the back-up roller assembly. At this time there is contact between the raised portions of the printing plates and the back-up roller so that the web of roll leaf is gripped therebetween and the web of roll leaf is advanced a distance equal to the Width of the imprinted legend. When the printing action of the imprinter ceases, the movement of the web of roll leaf also stops. Hence, even though the rewind shaft is constantly driven by the packaging machine, the roll leaf is intermittently withdrawn from the supply roll only when a legend is imprinted on the packaging film; this feature conserves the amount of roll leaf that is used by the imprinter.

(e) Operation of the imprinter After an imprinter of the present invention is installed on a packaging machine in the manner described above, the web 4 of packaging film is threaded between the back-up roller of the back-up roller assembly and the printing plate cylinder of the printing plate cylinder assembly, and thence over a draw roll 145 which is driven by chain 40 from the main drive shaft 39 of the imprinter. From the draw roll 145, the web of packaging film 4 is fed onto the rotatable drum 7 of the packaging machine. In a packaging machine 2 the type illustrated, the draw roll 145 is driven by the motor associated with the packaging machine through a differential unit and the web is selectively stretched by controlling the rotational speed of the draw roll so that each design 22 on the web 4 will be properly positioned with respect to a containerforming cavity 0n the vacuum-forming drum of the packaging machine. Appropriate differential driving means and photoelectric sensing units, not shown in the drawings, are incorporated for this purpose. When installing the imprinter of the present invention on a packaging machine, it is generally desirable that the draw roll unit of the machine be inactivated so that the printing plate cylinder can be run in synchronism with the vacuumforming drum of the packaging machine; when this is the case, the imprinter will'include a draw roll assembly 145 of the type normally used by the machine but the construction of the draw roll assembly itself is not a feature of the present invention. The shaft 30 of the machine 2 upon which the imprinter is installed would normally be 9 a shaft for carrying a supply roll of the web 4; for this reason, the imprinter 1 will include a shaft 5 to provide for mounting the supply roll of web 4.

The web 117 of roll leaf is then threaded between the supply reels and rewind shaft so that it passes between the back-up roller and the printing plate cylinder, being positioned between the printing plate cylinder and the web of packaging film. The drive means for driving the back-up roller assembly and, hence, the printing plate cylinder assembly, from the packaging machine has gears and sprockets of suitable size so that the printing plates on the cylinders 106 will be driven at the same linear speed as the vacuum-forming drum 7 of the packaging machine, or the equivalent movable member on machines which have an element other than a vacuum-forming drum on which packaging film is received. By driving the printing plate cylinder in this relation to the vacuumforming drum speed, the imprinted legend will be in proper registry with a pre-printed design on the web for packaging film.

The air cylinders 74 are actuated to place the back-up roller assembly 45 into its first, or lowermost, position wherein the rubber-covered roller 81 will be in position to exert pressure on the raised portions of printing plates 21 carried on the printing plate cylinders 106 and the webs of packaging film and roll leaf in order to cause transfer of the roll leaf from the web 117 onto the web 4. The electrical heater 103 inside the hollow central shaft 85 of the printing plate cylinder is heated to an appropriate temperature to effect such transfer, generally on the order of ZOO-400 P. Then, when the packaging machine is turned on, the back-up rollers and the printing plate cylinders will be turning at the appropriate speed and each time a printing plate comes into position underneath the backup roller, a legend will be imprinted on the web of packaging film, there being sufficient heat and pressure to effect transfer of the roll leaf. At this time, the web of roll leaf will be advanced a distance slightly greater than the width of the imprinted legend and used roll leaf is wound onto the rewind shaft. After the printing plates pass underneath the back-up roller, movement of the web of roll leaf stops. It has been found that the driving of the printing plate cylinder assembly at the same linear speed as the vacuum-forming drum of the packaging machine provides for proper registration of the imprinted legend in relation to a pre-printed design on the web 4 of packaging film. However, should this imprinted legend become out-of-registry during operation of the machine, the operator can turn the manual shaft 60 of the back-up roller assembly and alter the relative position of the printing plates with respect to the Web of packaging film to bring the imprinted legend back into proper registry. Turning the shaft 60 in one direction will advance the position of the printing plates relative to the web 4 and turning in the opposite direction will retard such position. The manual control thus lends to the proper functioning of the imprinter apparatus.

When the packaging machine is turned off, the air cylinders 74 operate to move the back-up roller assembly to its second, or raised, position in which the back-up roller is out of contact with the web 4 of packaging film. This prevents damage to the web of packaging film since if the back-up roller is left in its first position where it contacts the web 4, there is a possibility of burning through and/ or rupturing the packaging film. When the back-up roller assembly is raised in this fashion (generally about /8 is sufiicient), the driving gear 86 on the shaft 48 of the back-up roller assembly will also move upward but remain in engagement with the gear 87 stationarily attached to the imprinter frame; however, it has been found that with this arrangement, the gear 86 will stay meshed with the gear 87 even though the back-up roller assembly moves up and down and the printing plate 10 cylinders will remain in proper registry with packaging film.

Whenever it is desired to change the printing plates on the printing plate cylinder assembly, the assembly 20 can he slid out of the frame of the imprinter as an integral unit (see FIG. 12), the heater 103 remaining in position since it is attached to a side wall of the frame. After being withdrawn from the imprinter frame, the printing plates 21 on the cylinders 106 can be rapidly removed because they are held on by magnets. This feature therefore facilitates rapid change of the printing plates so that when the product being packaged by the packaging machine 2 is changed, a different imprinted legend can be applied by the imprinter apparatus and there is only a very short interruption for performing this change.

There is thus described an imprinter apparatus capable of satisfying the objects of the present invention and which renders it possible to imprint an auxiliary legend on a web of packaging film being used by a packaging machine to enclose commodity. This is accomplished by a dependable, economical apparatus which can be attached to the packaging machine without modifying it. It is understood that it is intended to cover all changes and modifications of the imprinter of this invention herein illustrated which do not constitute a departure from the spirit and scope of this invention.

We claim:

1. For use with a packaging machine of the type adapted to receive a web of packaging film and enclose commodity therein to form individual packages, said packaging machine including a driving motor driving a movable member at a selected linear speed and for drawing the web of packaging film onto the movable member, and wherein the web may include a pro-printed design,

an imprinter for imprinting a legend onto the web of packaging film as it is drawn into the packaging machine, said imprinter comprising:

a frame including a beam adapted for attachment to the packaging machine and spaced side walls supported from the beam;

a pair of pivotable support arms, one such arm being attached to each side wall so that each of said arms is pivotable between a first and a second position, and means for moving said arms into their first position when the imprinter is operated and into their second position when the imprinter is not operating;

a back-up roller assembly including a central shaft journalled in said pivotable support arms, a back-up roller on the central shaft and a first driving gear attached to the central shaft;

a printing plate cylinder assembly including a hollow central shaft, a cylinder on the hollow central shaft, at least one printing plate on the cylinder, magnet means for holding each printing plate in a fixed position on the cylinder, at second driving gear attached to the hollow central shaft, and a support member including a bottom and spaced end walls wherein sa1d hollow central shaft is journaled in said end walls and said support member is carried in the frame of the lmprinter and adapted for removal therefrom;

gear means fixed to one of the side Walls of the imprinter and meshing with the first driving gear on the central shaft of the back-up roller assembly and with the second driving gear on the hollow shaft of the printing plate cylinder assembly so that rotation of said first driving gear will cause rotation of said second driving gear;

driving means attached to the central shaft of the backup roller assembly, said driving means being adapted for connection to said driving motor of the packaging machine to rotate the printing plate cylinder at the same linear speed as said movable member of the packaging machine;

means for supplying a web of roll leaf between the back-up roller assembly and printing plate cylinder the web of assembly, said means comprising a supply shaft journaled in the frame of the imprinter and a supply reel for carrying a web of roll leaf mounted on the supply shaft, a rewind shaft journaled in the frame of the imprinter, slipping clutch means on the rewind shaft for receiving a web of roll leaf, means for driving the rewind shaft from said driving motor of the packaging machine, and brake means for exerting tension on a web of roll leaf carried on the supply roll, wherein the tension exerted by said slipping clutch means on a web of roll leaf threaded between the supply reel and the rewind shaft is less than the tension exerted on the web by said braking means so that no roll leaf will be transferred onto the rewind shaft as the rewind shaft rotates during operation of the packaging machine except when an imprinted legend is applied to .a web of packaging film threaded through the imprinter;

heating means extending within the hollow shaft of the printing plate cylinder assembly;

wherein a web of packaging material film passing between the back-up roller and the printing plate cylinwill be imprinted wit-h roll leaf transferred from a web thereof carried by the roll leaf supply system upon the application of heat from the heating means and upon passage of the packaging film between the back-up roller in its said first position and the printing plate cylinder, and wherein the web of roll leaf is advanced during such imprinting action to present fresh roll leaf for another imprinted legend. For use with a packaging machine of the type adapted to receive a Web of packaging film and enclose commodity therein to form individual packages, said packaging ma-chine including a driving motor for driving a movable member at a selected linear speed and for drawing the web of packaging film into the machine, and wherein the web may include a pre-printed design,

an imprinter for imprinting a legend onto the web of packaging film as it is drawn into the packaging machine, said imprinter comprising:

frame adapted for attachment to the pack-aging machine;

a pair of spaced pivotable support arms mounted in said frame so that each of said arms is pivotable between a first and a second position, and means for moving said arms to their first position when the imprinter is operated and to their second position when the imprinter is not operating;

a back-up roller assembly including a central shaft jourgear means fixed to the frame of the imprinter and meshing with the first driving gear on the central shaft of the back-up roller assembly and with the second driving gear on the hollow shaft of the printing plate cylinder assembly so that rotation of said first driving gear will cause rotation of said second driving gear;

driving means attached to the central shaft of the back up roller assembly, said driving means being adapted for connection to the driving motor of the packaging machine for rotating the central shaft of the back-up roller assembly and the central shaft of the printing plate cylinder assembly;

means for supplying a web of roll leaf between the back up roller assembly and printing plate cylinder assembly and adapted to hold a web of roll leaf in a stationary position but to allow movement of said web when a legend is imprinted;

heating means extending within the hollow shaft of the printing plate cylinder assembly;

wherein a web of packaging material film passing between the back-up roller and the printing plate cylinder will be imprinted with roll leaf transferred from a web thereof carried by the roll leaf supply system upon the application of heat from the heating means and upon passage of the packaging film between the back-up roller in its said first position and a printing plate on the printing plate cylinder, and wherein the web of roll leaf is advanced during such imprinting action to present fresh roll leaf for another imprinted legend.

3. For use with a packaging machine of the type adapted to receive a web of packaging film and enclose commodity therein to form individual packages, said packaging machine including a driving motor for driving a movable member at a selected linear speed and for drawing the Web of packaging film into the machine, and wherein the web may include a pre-printed design,

an imprinter for imprinting a legend onto the web of packaging film as it is drawn into the packaging machine, said imprinter comprising:

a frame adapted for attachment to the packaging machine;

a back-up roller assembly including a central shaft, a back-up roller on the central shaft and a first driving gear attached to the central shaft;

pivotal means for supporting the back-up roller assembly in the frame of the imprinter;

means for selectively moving said pivotal means into a first position in which the back-up roller is in an imprinting position and out of said first position;

a printing plate cylinder assembly including a central shaft, a cylinder on the central shaft, at least one printing plate carried on the cylinder, magnet means for holding each printing plate in a fixed position on the cylinder, and a second driving gear attached to the hollow central shaft;

a support member in which the central shaft of the printing plate cylinder assembly is journaled and which is adapted for mounting in the frame of the imprinter;

gear means fixed to the frame of the imprinter and meshing with the first driving gear on the central shaft of the back-up roller assembly and with the sec ond driving gear on the central shaft of the printing plate cylinder assembly so that rotation of said first driving gear will cause rotation of said second driving gear;

driving means attached to the central shaft of the backup roller assembly and adapted for connection to the driving motor of the packaging machine for rotating the back-up roller and printing plate assemblies;

means for supplying a web of roll leaf between the back-up roller assembly and printing plate cylinder assembly and adapted to hold a web of roll leaf stationary when the imprinter is not imprinting a legend and to allow movement of a web of roll leaf when a legend is imprinted;

heating means for heating the plate cylinder of the printing plate cylinder assembly for transfer of roll leaf;

wherein a web of packaging material film threaded between the back-up roller and the printing plate cylinder will be imprinted with roll leaf transferred from a web thereof carried by the roll leaf supply system upon the application of heat from the heating means and upon passage of the packaging film between the back-up roller in its said first position and the printing plate cylinder, and wherein such web of roll leaf is advanced during said imprinting action to present fresh roll leaf for another imprinted legend.

4. For use with a packaging machine of the type adapted to receive a web of packaging fihn and enclose commodity therein to form individual packages, said packaging machine including a driving motor for driving a movable'member at a selected linear speed and for drawing the web of packaging film into the machine, and wherein the web may include a pre-printed design,

an imprinter for imprinting a legend onto the web of packaging film as it is drawn into the packaging machine, said imprinter comprising:

a frame adapted for attachment to the packaging machine;

a back-up roller assembly pivotably mounted in said frame and including a central shaft and a back-up roller on the central shaft;

a printing plate cylinder assembly mounted in a support member and including a central shaft, a cylinder on the central shaft for carrying at least one printing plate, and magnet means for holding each printing plate in a fixed position on the cylinder, said support member being carried in the frame of the imprinter and adapted for removal therefrom;

driving means attached to the central shaft of the backup roller assembly and adapted for connection to the driving motor of the packaging machine for rotating the back-up roller assembly;

means for driving the printing plate cylinder assembly from the back-up roller assembly;

means for supplying a web of roll leaf between the back-up roller assembly and printing plate cylinder assembly;

heating means for heating the cylinder of the printing plate cylinder assembly to effect transfer of roll leaf;

wherein a web of packaging material film threaded between the back-up roller and the cylinder of the printing plate cylinder assembly will be imprinted with roll leaf transferred from a web thereof carried by the roll leaf supply system upon the application of heat from the heating means and upon passage of the packaging film between theback-up roller and printing plates on the printing plate cylinder assembly.

5. For use with a packaging machine of the type adapted to receive a web of packaging film and enclose commodity therein to form individual packages, said packaging machine including a driving motor for driving a movable member at a selected linear speed and for drawing the web of packaging film into the machine, and wherein the web may include a pre-printed design,

an imprinter for imprinting a legend onto the web of packaging film as it is drawn into the packaging machine, said imprinter comprising: a frame adapted for attachment to the packaging machine;

a back-up roller assembly including a central shaft, a back-up roller on the central shaft and a first driving gear attached to the central shaft;

pivotal means for supporting the back-up roller assembly in the frame of the imprinter;

means for selectively moving said pivotal means into a first position in which the back-up roller is in an imprinting position and out of said first position;

a printing plate cylinder assembly including a central shaft, a cylinder on the central shaft for carrying printing plates, and a second driving gear attached to the hollow central shaft;

a support member in which the central shaft of the printing plate cylinder assembly is journaled and which is adapted for mounting in the frame of the imprinter;

gear means fixed to the frame of the imprinter and meshing with the first driving gear on the central shaft of the back-up roller assembly and with the second driving gear on the central shaft of the printing plate cylinder assembly so that rotation of said first driving gear will cause rotation of said second driving gear;

driving means attached to the central shaft of the backup roller assembly and adapted for connection to the driving motor of the packaging machine for rotating the back-up roller and printing plate assemblies;

means for supplying a web of roll leaf between the back-up roller assembly and printing plate cylinder assembly and adapted to hold a web of roll leaf stationary when the imprinter is not imprinting a legend and to allow movement of a web of roll leaf when a legend is imprinted;

heating means for heating the plate cylinder of the printing plate cylinder assembly for transfer of roll leaf;

wherein a web of packaging material film threaded between the back-up roller and the printing plate cylinder will be imprinted with roll leaf transferred from a web thereof carried by the roll leaf supply system upon the application of heat from the heating means and upon passage of the packaging film between the back-up roller in its said first position and the printing plate cylinder, and wherein such web of roll leaf is advanced during said imprinting action to present fresh roll leaf for another imprinted legend.

References Cited by the Examiner UNITED STATES PATENTS 1,939,081 12/1933 Prager 101- 25 1,949,362 2/ 1934- Wickwire 10l25 2,288,298 6/1942 Norman et a1. 1018 ROBERT E. PULFREY, Primary Examiner.

W. MCCARTHY, Assistant Examiner. 

4. FOR USE WITH A PACKAGING MACHINE OF THE TYPE ADAPTED TO RECEIVE A WEB OF PACKAGING FILM AND ENCLOSE COMMODITY THEREIN TO FORM INDIVIDUAL PACKAGES, SAID PACKAGING MACHINE COMPRISING A DRIVING MOTOR FOR DRIVING A MOVABLE MEMBER AT A SELECTED LINEAR SPEED AND FOR DRAWING THE WEB OF PACKAGING FILM INTO THE MACHINE, AND WHEREIN THE WEB MAY INCLUDE A PRE-PRINTED DESIGN, AN IMPRINTER FOR IMPRINTING A LEGEND ONTO THE WEB OF PACKAGING FILM AS IT IS DRAWN INTO THE PACKAGING MACHINE, SAID IMPRINTER COMPRISING: A FRAME ADAPTED TO ATTACHMENT TO THE PACKAGING MACHINE; A BACK-UP ROLLER ASSEMBLY PIVOTABLY MOUNTED IN SAID FRAME AND INCLUDING A CENTRAL SHAFT AND A BACK-UP ROLLER ON THE CENTRAL SHAFT; A PRINTING PLATE CYLINDER ASSEMBLY MOUNTED IN A SUPPORT MEMBER AND INCLUDING A CENTRAL SHAFT, A CYLINDER ON THE CENTRAL SHAFT FOR CARRYING AT LEAST ONE PRINTING PLATE, AND MAGNET MEANS FOR HOLDING EACH PRINTING PLATE IN A FIXED POSITION ON THE CYLINDER, SAID SUPPORT MEMBER BEING CARRIED IN THE FRAME OF THE IMPRINTER AND ADAPTED FOR REMOVAL THEREFROM; DRIVING MEANS ATTACHED TO THE CENTRAL SHAFT OF THE BACKUP ROLLER ASSEMBLY AND ADAPTED FOR CONNECTION TO THE DRIVING MOTOR OF THE PACKAGING MACHINE FOR ROTATING THE BACK-UP ROLLER ASSEMBLY; MEANS FOR DRIVING THE PRINTING PLATE CYLINDER ASSEMBLY FROM THE BACK-UP ROLLER ASSEMBLY; MEANS FOR SUPPLYING A WEB OF ROLL LEAF BETWEEN THE BACK-UP ROLLER ASSEMBLY AND PRINTING PLATE CYLINDER ASSEMBLY; HEATING MEANS FOR HEATING THE CYLINDER OF THE PRINTING PLATE CYLINDER ASSEMBLY TO EFFECT TRANSFER OF ROLL LEAF; WHEREIN A WEB OF PACKAGING MATERIAL FILM THREADED BETWEEN THE BACK-UP ROLLER AND THE CYLINDER OF THE PRINTING PLATE CYLINDER ASSEMBLY WILL BEL IMPRINTED WITH ROLL LEAF TRANSFERRED FROM A WEB THEREOF CARRIED BY THE ROLL LEAF SUPPLY SYSTEM UPON THE APPLICATION OF HEAT FROM THE HEATING MEANS AND UPON PASSAGE OF THE PACKAGING FILM BETWEEN THE BACK-UP ROLLER AND PRINTING PLATES ON THE PRINTING PLATE CYLINDER ASSEMBLY. 